Well, now I've got these messages, first time during FO:NV, then during Hard Reset. I uninstalled the driver, ran CCleaner, and upgraded to the latest nvidia driver. Tested Hard Reset again and it was fine. Now DE:HR Missing Link did it to me.
I had been running the previous driver for a while with no issues, but did install BFBC and Crysis 2 last weekend, that would be the only other software change. Is this problem really that random or can it be solved eventually?
GTX560Ti, win7 x64, 4gb ram.

This problem seems to be endemic to the 560 Ti. I had it with my Galaxy card for numerous driver releases. I kept going back to version 275. But a recent update fixed the problem for me. If it's really troubling you, I'd suggest reverting to an older driver.